The project objective is to determine the metabolic changes that occur during temperature acclimation in Drosophila and to identify genetic and metabolic factors that limit the capacity of the animal to acclimate. Regulation of the oxidative NADP-enzymes appears basic to the temperature acclimation process. Research to date indicates that the tissue levels of glucose-6-phosphate dehydorgenase and 6-phosphogluconate dehydrogenase are induced by a glycolytic derivative and malic enzyme and NADP-isocirate dehydrogenase are induced by a Krebs cycle derivative. Tissue levels of all four enzymes are repressed by dietary lipid. Our current objectives are to more thoroughly characterize the regulatory systems for the tissue levels of the oxidative NADP-enzymes. By use of chromosomal translocations and chromosome interchange methods we plan to identify some of the regulatory loci and to determine if carbohydrate-lipid regulation of the oxidative NADP-enzymes is gene dosage sensitive. We also plan to correlate the modifications of lipid synthesis during cold acclimation with the concurrent modulation of the NADP-enzymes. BIBLIOGRAPHIC REFERENCE: Geer, B. W., S. N. Kamiak, K. R. Kidd, R. A. Nishimura and S. J. Yemm. 1976. Regulation of the oxidative NADP-enzyme tissue levels in Drosophila melanogaster. I. Modulation by dietary carbohydrate and lipid. Journal of Experimental Zoology, accepted for publication July 19, 1975.